crossing over


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crossing over

 
the exchanging of material between homologous chromosomes, during the first meiotic division, resulting in new combinations of genes.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

crossing over

or

crossing-over

(krô′sĭng-ō′vər, krŏs′ĭng-)
n.
The exchange of genetic material between homologous chromosomes that occurs during meiosis and contributes to genetic variability.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

crossing over

Recombination Vox populi A popular phrase for a change in a person's sexual preference, usually heterosexual → homosexual
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
Crossing overclick for a larger image
Fig. 123 Crossing over . The exchange of chromatid material.

crossing over

a process occurring in the DIPLOTENE stage of Prophase 1 of MEIOSIS in which there is exchange of nonsister CHROMATIDS, producing genetic RECOMBINATION. (see Fig. 123 ). See also UNEQUAL CROSSING OVER.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005